A brand-new official companion guide to the Rick Riordan books, set in the incredible world of Percy Jackson and The Trials of Apollo Mysterious incidents are wreaking havoc throughout Camp Jupiter. And if the Romans don't find out who -or what -is behind the episodes soon, the Twelfth Legion could implode. Suspicion falls on Claudia, the Fourth Cohort's newest probatio. To find out the truth, see through Claudia's eyes the crime scenes, and watch as the bizarre events unfold - even when she discovers a secret that holds the key to Camp Jupiter's safety...